!!! Multiple package instances within a single package slot have been pulled
!!! into the dependency graph, resulting in a slot conflict:

media-sound/jack-audio-connection-kit:0

(media-sound/jack-audio-connection-kit-0.121.3-r1::gentoo, ebuild scheduled for merge) pulled in by
media-sound/jack-audio-connection-kit[abi_x86_32(-)?,abi_x86_64(-)?,abi_x86_x32(-)?,abi_x86_32(-)?,abi_x86_64(-)?,abi_mips_n32(-)?,abi_mips_n64(-)?,abi_mips_o32(-)?] required by (media-libs/portaudio-19_pre20111121-r1::gentoo, ebuild scheduled for merge)

(media-sound/jack-audio-connection-kit-2.9999::proaudio, ebuild scheduled for merge) pulled in by
(no parents that aren't satisfied by other packages in this slot)

It may be possible to solve this problem by using package.mask to
prevent one of those packages from being selected. However, it is also
possible that conflicting dependencies exist such that they are
impossible to satisfy simultaneously. If such a conflict exists in
the dependencies of two different packages, then those packages can
not be installed simultaneously. You may want to try a larger value of
the --backtrack option, such as --backtrack=30, in order to see if
that will solve this conflict automatically.

and tried un-merging both jack-connection-kit and portaudio but they are still being pulled in and blocking.

What might I try next? Appreciate the help. --JD

[edit] I did try running emerge -avuNDt @world and that shows some packages that the kit is depending on. So I unmerged rosegarden, gst-plugins-jack, mpg123, but there's always others depending on the two jack-kits. I stopped at vlc. I need jack for ardour and a couple other things, hence it is in USE flags. Here's a snippet of the last emerge -avuNDt @world command: